001 /*
002 * Copyright 2007-2016 UnboundID Corp.
003 * All Rights Reserved.
004 */
005 /*
006 * Copyright (C) 2008-2016 UnboundID Corp.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU General Public License (GPLv2 only)
010 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
011 * as published by the Free Software Foundation.
012 *
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
016 * GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with this program; if not, see <http://www.gnu.org/licenses>.
020 */
021 package com.unboundid.ldap.sdk.controls;
022
023
024
025 import com.unboundid.asn1.ASN1Element;
026 import com.unboundid.asn1.ASN1OctetString;
027 import com.unboundid.asn1.ASN1Sequence;
028 import com.unboundid.ldap.sdk.Control;
029 import com.unboundid.ldap.sdk.LDAPException;
030 import com.unboundid.ldap.sdk.ResultCode;
031 import com.unboundid.util.NotMutable;
032 import com.unboundid.util.ThreadSafety;
033 import com.unboundid.util.ThreadSafetyLevel;
034
035 import static com.unboundid.ldap.sdk.controls.ControlMessages.*;
036 import static com.unboundid.util.Debug.*;
037 import static com.unboundid.util.Validator.*;
038
039
040
041 /**
042 * This class provides an implementation of the server-side sort request
043 * control, as defined in
044 * <A HREF="http://www.ietf.org/rfc/rfc2891.txt">RFC 2891</A>. It may be
045 * included in a search request to indicate that the server should sort the
046 * results before returning them to the client.
047 * <BR><BR>
048 * The order in which the entries are to be sorted is specified by one or more
049 * {@link SortKey} values. Each sort key includes an attribute name and a flag
050 * that indicates whether to sort in ascending or descending order. It may also
051 * specify a custom matching rule that should be used to specify which logic
052 * should be used to perform the sorting.
053 * <BR><BR>
054 * If the search is successful, then the search result done message may include
055 * the {@link ServerSideSortResponseControl} to provide information about the
056 * status of the sort processing.
057 * <BR><BR>
058 * <H2>Example</H2>
059 * The following example demonstrates the use of the server-side sort controls
060 * to retrieve users in different sort orders.
061 * <PRE>
062 * // Perform a search to get all user entries sorted by last name, then by
063 * // first name, both in ascending order.
064 * SearchRequest searchRequest = new SearchRequest(
065 * "ou=People,dc=example,dc=com", SearchScope.SUB,
066 * Filter.createEqualityFilter("objectClass", "person"));
067 * searchRequest.addControl(new ServerSideSortRequestControl(
068 * new SortKey("sn"), new SortKey("givenName")));
069 * SearchResult lastNameAscendingResult;
070 * try
071 * {
072 * lastNameAscendingResult = connection.search(searchRequest);
073 * // If we got here, then the search was successful.
074 * }
075 * catch (LDAPSearchException lse)
076 * {
077 * // The search failed for some reason.
078 * lastNameAscendingResult = lse.getSearchResult();
079 * ResultCode resultCode = lse.getResultCode();
080 * String errorMessageFromServer = lse.getDiagnosticMessage();
081 * }
082 *
083 * // Get the response control and retrieve the result code for the sort
084 * // processing.
085 * LDAPTestUtils.assertHasControl(lastNameAscendingResult,
086 * ServerSideSortResponseControl.SERVER_SIDE_SORT_RESPONSE_OID);
087 * ServerSideSortResponseControl lastNameAscendingResponseControl =
088 * ServerSideSortResponseControl.get(lastNameAscendingResult);
089 * ResultCode lastNameSortResult =
090 * lastNameAscendingResponseControl.getResultCode();
091 *
092 *
093 * // Perform the same search, but this time request the results to be sorted
094 * // in descending order by first name, then last name.
095 * searchRequest.setControls(new ServerSideSortRequestControl(
096 * new SortKey("givenName", true), new SortKey("sn", true)));
097 * SearchResult firstNameDescendingResult;
098 * try
099 * {
100 * firstNameDescendingResult = connection.search(searchRequest);
101 * // If we got here, then the search was successful.
102 * }
103 * catch (LDAPSearchException lse)
104 * {
105 * // The search failed for some reason.
106 * firstNameDescendingResult = lse.getSearchResult();
107 * ResultCode resultCode = lse.getResultCode();
108 * String errorMessageFromServer = lse.getDiagnosticMessage();
109 * }
110 *
111 * // Get the response control and retrieve the result code for the sort
112 * // processing.
113 * LDAPTestUtils.assertHasControl(firstNameDescendingResult,
114 * ServerSideSortResponseControl.SERVER_SIDE_SORT_RESPONSE_OID);
115 * ServerSideSortResponseControl firstNameDescendingResponseControl =
116 * ServerSideSortResponseControl.get(firstNameDescendingResult);
117 * ResultCode firstNameSortResult =
118 * firstNameDescendingResponseControl.getResultCode();
119 * </PRE>
120 * <BR><BR>
121 * <H2>Client-Side Sorting</H2>
122 * The UnboundID LDAP SDK for Java provides support for client-side sorting as
123 * an alternative to server-side sorting. Client-side sorting may be useful in
124 * cases in which the target server does not support the use of the server-side
125 * sort control, or when it is desirable to perform the sort processing on the
126 * client systems rather than on the directory server systems. See the
127 * {@link com.unboundid.ldap.sdk.EntrySorter} class for details on performing
128 * client-side sorting in the LDAP SDK.
129 */
130 @NotMutable()
131 @ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
132 public final class ServerSideSortRequestControl
133 extends Control
134 {
135 /**
136 * The OID (1.2.840.113556.1.4.473) for the server-side sort request control.
137 */
138 public static final String SERVER_SIDE_SORT_REQUEST_OID =
139 "1.2.840.113556.1.4.473";
140
141
142
143 /**
144 * The serial version UID for this serializable class.
145 */
146 private static final long serialVersionUID = -3021901578330574772L;
147
148
149
150 // The set of sort keys to use with this control.
151 private final SortKey[] sortKeys;
152
153
154
155 /**
156 * Creates a new server-side sort control that will sort the results based on
157 * the provided set of sort keys.
158 *
159 * @param sortKeys The set of sort keys to define the desired order in which
160 * the results should be returned. It must not be
161 * {@code null} or empty.
162 */
163 public ServerSideSortRequestControl(final SortKey... sortKeys)
164 {
165 super(SERVER_SIDE_SORT_REQUEST_OID, false, encodeValue(sortKeys));
166
167 this.sortKeys = sortKeys;
168 }
169
170
171
172 /**
173 * Creates a new server-side sort control that will sort the results based on
174 * the provided set of sort keys.
175 *
176 * @param isCritical Indicates whether this control should be marked
177 * critical.
178 * @param sortKeys The set of sort keys to define the desired order in
179 * which the results should be returned. It must not be
180 * {@code null} or empty.
181 */
182 public ServerSideSortRequestControl(final boolean isCritical,
183 final SortKey... sortKeys)
184 {
185 super(SERVER_SIDE_SORT_REQUEST_OID, isCritical, encodeValue(sortKeys));
186
187 this.sortKeys = sortKeys;
188 }
189
190
191
192 /**
193 * Creates a new server-side sort request control which is decoded from the
194 * provided generic control.
195 *
196 * @param control The generic control to be decoded as a server-side sort
197 * request control.
198 *
199 * @throws LDAPException If the provided control cannot be decoded as a
200 * server-side sort request control.
201 */
202 public ServerSideSortRequestControl(final Control control)
203 throws LDAPException
204 {
205 super(control);
206
207 final ASN1OctetString value = control.getValue();
208 if (value == null)
209 {
210 throw new LDAPException(ResultCode.DECODING_ERROR,
211 ERR_SORT_REQUEST_NO_VALUE.get());
212 }
213
214 try
215 {
216 final ASN1Element valueElement = ASN1Element.decode(value.getValue());
217 final ASN1Element[] elements =
218 ASN1Sequence.decodeAsSequence(valueElement).elements();
219 sortKeys = new SortKey[elements.length];
220 for (int i=0; i < elements.length; i++)
221 {
222 sortKeys[i] = SortKey.decode(elements[i]);
223 }
224 }
225 catch (Exception e)
226 {
227 debugException(e);
228 throw new LDAPException(ResultCode.DECODING_ERROR,
229 ERR_SORT_REQUEST_CANNOT_DECODE.get(e), e);
230 }
231 }
232
233
234
235 /**
236 * Encodes the provided information into an octet string that can be used as
237 * the value for this control.
238 *
239 * @param sortKeys The set of sort keys to define the desired order in which
240 * the results should be returned. It must not be
241 * {@code null} or empty.
242 *
243 * @return An ASN.1 octet string that can be used as the value for this
244 * control.
245 */
246 private static ASN1OctetString encodeValue(final SortKey[] sortKeys)
247 {
248 ensureNotNull(sortKeys);
249 ensureTrue(sortKeys.length > 0,
250 "ServerSideSortRequestControl.sortKeys must not be empty.");
251
252 final ASN1Element[] valueElements = new ASN1Element[sortKeys.length];
253 for (int i=0; i < sortKeys.length; i++)
254 {
255 valueElements[i] = sortKeys[i].encode();
256 }
257
258 return new ASN1OctetString(new ASN1Sequence(valueElements).encode());
259 }
260
261
262
263 /**
264 * Retrieves the set of sort keys that define the desired order in which the
265 * results should be returned.
266 *
267 * @return The set of sort keys that define the desired order in which the
268 * results should be returned.
269 */
270 public SortKey[] getSortKeys()
271 {
272 return sortKeys;
273 }
274
275
276
277 /**
278 * {@inheritDoc}
279 */
280 @Override()
281 public String getControlName()
282 {
283 return INFO_CONTROL_NAME_SORT_REQUEST.get();
284 }
285
286
287
288 /**
289 * {@inheritDoc}
290 */
291 @Override()
292 public void toString(final StringBuilder buffer)
293 {
294 buffer.append("ServerSideSortRequestControl(sortKeys={");
295
296 for (int i=0; i < sortKeys.length; i++)
297 {
298 if (i > 0)
299 {
300 buffer.append(", ");
301 }
302
303 buffer.append('\'');
304 sortKeys[i].toString(buffer);
305 buffer.append('\'');
306 }
307
308 buffer.append("})");
309 }
310 }